Tutorial: Getting Started with Protege-Frames
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Creating a relationship using slots
Protege-Frames also allows you to create slots that can be used to describe relationships between classes that are not defined by the class hierarchy. This can be done using slots of type Instance or of type Class. For example, an editor may be responsible for one or more employees. We can create a slot that represents this relationship between the Editor and Employee classes as follows:
  1. Select Editor in the Class Hierarchy pane.



  2. Click the Create Slot button to create and attach a new slot to Editor.



  3. In the resulting slot form, type responsible_for in the Name field.



  4. Select Instance from the Value Type menu.



    A new field, Allowed Classes, is displayed below the Value Type menu.



  5. Click the Add Class button that appears at the top right of the Allowed Classes area. A Select Classes dialog box displays all the classes in the project. Select Employee and click OK.



  6. To allow an editor to be responsible for more than one employee, click multiple in the Cardinality area to the right of the Value Type area.




After completing steps 1 through 6, the slot form for responsible_for looks as follows:



What have we done? We have created a slot that can hold one or more instances of the Employee class as its value. Later, when we create an instance of the Editor class, and we want to specify who that editor is responsible for, we can choose one or more instances of the Employee class to fill in the value of the responsible_for slot.